Research on a UV-assisted chemical modification strategy for monocrystalline silicon

Abstract. A novel UV-assisted chemical modification (UVA-CM) strategy is proposed for micro-grinding monocrystalline silicon based on UV photocatalysis theory in order to develop a combined machining technology. Comparative experiments are carried out between a single heating chemical modification (H-CM) strategy and a hybrid UVA-CM strategy. The effects of different modification strategies on modification degree and mechanical properties of a modified layer are evaluated by inductively coupled plasma mass spectrometry (ICP), Raman spectral analysis, nanoindentation test, and scratch test. The experimental results show that silicate substance is generated on the modified layer surface via the UVA-CM technique. The modified layer under UVA-CM is thicker than that under the H-CM strategy, which also presents relatively lower nanohardness. With the same scratch condition, the modified layer under UVA-CM contributes to inhibiting lateral crack propagation. It is demonstrated that the liquid–solid chemical modification effect is obviously enhanced through UV advanced oxidation reaction. The UVA-CM strategy will contribute to developing a novel hybrid chemo-mechanical process for micro-grinding monocrystalline silicon.